Professional photographic images are often obtained in an artificially lighted environment. Example types of images captured in this environment include school portraits, printed publication images, product packaging or marketing images, and athletic or club portraits. It is sometimes desirable to change the background behind the subject of the image, which requires additional processing of the image after its capture. Some existing methods for background replacement, such as chroma key, accomplish this objective but the resulting images can lack the crisp precision expected from professionally-captured photographs.
Other background replacement systems rely upon the creation of a mask that identifies the placement of the subject in the image. Techniques for creating the mask work well with very high speed photography methods or with relatively stationary subjects. But when the subject is moving, many camera systems cannot capture images fast enough to allow an accurate mask to be generated.